A standard-volume interscalene brachial plexus block causes ipsilateral phrenic nerve block, and therefore hemidiaphragmatic paresis, in most patients. Healthy patients tolerate it, but those with severe COPD, obesity hypoventilation, contralateral diaphragm weakness or limited respiratory reserve may not. For them, weigh lower volumes, a more distal approach such as a superior trunk or suprascapular-based technique, or local infiltration, and discuss the risk before surgery.
- Expect ipsilateral hemidiaphragmatic paresis after a standard interscalene block.
- Assess respiratory reserve before offering an interscalene block.
- Consider lower volumes or a more distal block in patients with limited reserve.
- Local infiltration is an option when a phrenic-sparing technique is not available.
Why it matters
The block recommended for shoulder surgery is the one most likely to compromise breathing in a vulnerable patient.
Read the rest in the app
You have read your two free briefings this month. The app carries all 27 specialties, every morning, free — and this finding is waiting in it.
Scan to keep reading on your phone. No account needed to start.
Tomorrow morning, before your first patient
One edition a day for anaesthesiology, written by the desk, every claim tied to its paper. Six minutes.
Get the app — free